Generally speaking, if the condom is placed on the penis, and inserted into the vagina, it will stay in place as long as the penis is erect, leaving the hands free to move on to other things. On some occasions if air was not removed before putting on the condom or the condom was not rolled down the entire length of the penis, it could roll and slip off. Another situation where it might come off is with too much lubricant being used or after ejaculation when he is losing his erection. It's recommended to hold the condom at the base of the penis when pulling out of the vagina while the penis is still hard so that the condom doesn't come off.